Backlash eliminator



Sept. 14, 1937.l E. H. MccouL BACI/{LA SH ELIMINATOR Filed March 21, 19:56v

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ATTORNEY Patented Sept. 14, 1937 B AcKLAsH EIJMINA'roIt'. v L j Edward n. Me coul, Thomaston, oonii.,`assignor 1 'fio-Seth 'ThomasClock Compan Thomaston.A

Conn., a. corporation of Conn ecticut vApplitetitni. Mm-en 21,1936, serial No. '10,014 solenne. (o1. 'zi- 440) Myinvention relates to backl lasheliminators and has forits object the production of a device for thisrpurpose which occupies a minimum of axial space, is extremely simple, easy to assemble and inexpensiveto prduceand decidedly positive in its action in the elimination of back lashin gear trains where great accuracy is required such as those usedin clock movements for driving charts and the like.

.I accomplish-these objects by the. means shown in the accompanyingdrawing in which:v f y Fig. 1 is a side viewof my back lash eliminator.

Fig. 2 is a cross sectional view along a line 2?' 2 of Figure 1 hving the kshaitnot shown lin `cross Fig. 3 is an enlarged `partial view ofy theparts shoWninFigurel. H .d

Fig. 4 is a separate view of the shaft portion of my back lash eliminator.

Fig. 5 is a side view of the stationary gear member which is rigidly mounted on the shaft shown in Figure 4.

Fig. 6 is an end view of the gear member shown in Figure 5.

Fig. 7 is a side view of yielding gear member of my back lash eliminator which is journaled on the shaft shown in Figure 4.

Fig. 8 is an end view of the gear member shown in Figurei'. Fig. 9 shows one of the resiliently or yielding member spiral spring members used to keep the proper tension between the gear members.

Fig. 10 is an end view of Figure 9.1 Similar numerals represent the same parts throughout the several views.

In the drawing I represents a shaft having the plurality of shoulders 5, 6 and 1 shown. Journaled on the shouldered part 5 is a gear Wheel 3 which is held in its rotating sidewise position by the larger shoulder 6 on ornev side of said wheel 3 and the other side of said wheel 3 by a similarly constructed gear wheel 2 which is rigidly mounted on a bushing 8 which is rigidly mounted on the special shoulder I of said shaft I. .The gear l wheel 3 is thus free to rotate on the shaft I while the gear wheel 2 rotates with the shaft I.' The gear Wheels 2 and 3 in addition to the regularly centrally disposed apertures each have a plurality of elongated concentrically disposed apertures 9 each of which has a substantially oentrally disposed tongue or projection I0 at, each of the ends of said apertures, as shown. The said apertures in the wheels 2 and 3 being similarly positioned such that when the wheels are mount- 5 ea on the shaft I, as above set forth, they win Ateeth will always be held illustrative of any and all register with. each other .as :showni 'iniFigures 1 and 3. When the-apertures 9 in saldgearfwheels 2 and 3 are thus brought intothe position of reg'- istration asubstantially long `spiral spring II of suitable diameter is compressed and inserted in f5 said raperture SI and released and. allowed yto .expand so that the interior opening in thecoil being sufficiently large will pass over and .onto the tongues-I0 which -tongues I0 and.the'sidessoftheV aperture-'ahold each of the said'springs vI I 'in its "10 operative-position. y .11 vri:

It is evident ,any rotation ofthe journaled. gear wheel. 3-while thegear 2 on shaft Iis held against rotation-Will immediately compress said spring'I I and thus create a pressurefor Vforce4 tending to 15 keep the apertures 9 in position of registration.

, Now, if the gear Wheels 2- and 3 are thus'posi-` tioned furtherapart Lto further vcompress 'the spring II and the teeth of the gear wheels 2 and 3 are in this position put intomesh with a gear 2o or pinion I2 as shown in Figure 1 it is seen that the teeth of gears 2 and 3 will grip the thus engaged teeth of the gear I2 so that the driving gear against the engaged teeth of the driven gear. It is evident that this 25 entirely eliminates vany back lashbetween th driven gear 2 andthe driving gear I2.

It is evidentthat both the gears Zand 3 may be suitably journaled on the shaft I so thatgthev combined gears 'can be used as an idler in a gear 80l train between two' other gears, instead of having one or the other of these gears fastened on the shaft and the remaining gear 'journaledgthereom Itisfevidentfrom the above that I have produced a back lash eliminator kwhich is extremelyV 35 simple and inexpensive to produce and to asseme ble and which is decidedly positivey in its action. It will vbe understood, of course, that while I have here shown one form of my lback Alash elimmater 1 do not wish to be limited to the emetaofA form shown but desire to haveit taken in a sensey forms' which come fairly within the scope of.' the appended claims.

I claim:

1. A back lash eliminator comprising a p1u- 45` rality ofgear wheels journally mounted on a shaft, said wheels having one or more similar apertures,` opposed spaced, tongues in said apertures andcoiled springs retained on said tongues in said apertures for supplying a restoring force 50 4 whenever an angular displacement occurs between said wheels.

2. A backlash eliminator comprlsingaplurality of gear wheels each journally mounted side by side on a shaft, each of said wheels having f apertures and a spiral spring compressed `and r positioned over said tongues of both of said wheels l5 and thereby retained thereon, and tendingV to keep said opposed membersin registration Vvwith eachother. .i i

4. A back lash eliminator comprising a plurality of gear wheels each journally mounted side y 20 by lside on a shaft, each of said wheels having one or-more :substantially similar .concentric apertures; opposed spaced tongues in each of said apertures and a spiral spring compressed. and positioned over saidv tongues of rvboth .of said 25 wheels and thereby retained 4thereon,'resiliently keeping said members in registration wlthfeach Other.; -1 ff D y 5. A backlash eliminator` comprising.v a Vplurality of gear Wheels each journally mounted side n 3Q by side on a shaftfeach of said Wheels having one or more substantially similar apertures; opposedspaced tongues in each of said apertures and resilient means-positioned over said tongues of both of said wheels and thereby retained there- 35 on, resiliently keeping said members in registration with each other. 'I'

6..A back lash eliminator comprising a plu'- rality oi' -gear wheels each Journallv mounted side by side on a shaft, each of said wheels having one or more substantially similar concentric apertures, opposed spaced tongues in each of said' apertures and resilient means positioned over f said tongues of both of said wheels and thereby retained thereon, resiliently keeping said concentric apertures in registration with each other.

'1. ,A back lash eliminator comprisinga shaft, a gear Wheelhaving an aperture rigidly mounted on said shaft, an auxiliary gear wheel having a substantially similar aperture journally mounted on said shaft, opposed spaced tongues in the aperture of each of said wheels and` cofacting resilient. means .positioned over the said tonguesvvof both of said wheels and thereby retained, thereon, resiliently keeping said members in registration with each other.

8. A backl lash eliminator comprising a shaft,

a geanwheel having an aperture rigidly mounted on'said shaft, an auxiliary gear wheel having an aperture journally mounted ori'said shaft, opposed spaced tonguesin" the aperture of each 'of said wheels and colacting resilientmeans posi# tioned over the saidftongues of b'othy r of said wheelsfresiliently keeping 4said. members in registration with eachr other. e i. Af

l9. yAlback lash eliminator comprising a'shaft,

a gear-*wheel having anaperturerigidly'niounted on saidy shaft, ari auxiliary gear 'wheel'having a substantially similar aperture'journally mounted on said' shaft, opposed-spaced tonguesi'n the aperture of each-of said .wheels and co-acting resilient means posiitoned over and'arundthe said tongues of both of saidwheels vand exerting a substantial force between the teeth of said wheelsl when said opposed members are not in registration with eachother. l e

. EDWARD H. MlicCOU'I...`

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